Problem: Rewrite ${((9^{-10})(4^{8}))^{-5}}$ in the form ${9^n \times 4^m}$.
Explanation: ${ ((9^{-10})(4^{8}))^{-5} = (9^{(-10)(-5)})(4^{(8)(-5)})} $ ${\hphantom{ ((9^{-10})(4^{8}))^{-5}} = 9^{50} \times 4^{-40}} $